Vitamin D in Different Stages of Type 2 Diabetic Nephropathy and its Correlation with Transforming Growth Factor Beta-1 (TGF-β1) –A Cross Sectional Study

Background: Diabetic nephropathy (DN) is a microvascular complication of Diabetes Mellitus (DM) and the prevalence of which is increasing in every year. Monitoring of Vitamin D status in diabetic nephropathy patients is important, as the deficiency of vitamin D appears as a risk factor for the development of diabetic nephropathy. Studies evaluating the role of vitamin D in DN are few. Conflicting data is available on the correlation between vitamin D and Diabetic Nephropathy. Studies revealed the sample population is Vitamin D deficient. Therefore, it is important to understand the correlation of Vitamin D with severity of Diabetic nephropathy and its role in fibrogenesis. The aim of this study is to analyse vitamin D status in different stages of type 2 diabetic nephropathy and its correlation with transforming growth factor beta-1.

Methods: A 1.5-year cross-sectional study of 120 diabetic patients, 60 with nephropathy and 60 without nephropathy patients enrolled to MES Medical College. Patients with heart, liver, or thyroid disease, as well as those on dialysis, were excluded from the study. The VITROS 5600 integrated system were used to measure fasting blood sugar (FBS), HbA1c, creatinine and vitamin D. Transforming Growth Factor Beta-1 (TGF-β1) is measured using ELISA technique. According to HbA1c and estimated glomerular filtration rate (eGFR) values, the study population is divided into two groups. The statistical package for the social sciences (SPSS) software was used to conduct the analysis. The level of significance was calculated at 95%.

Results: The level of vitamin D in diabetic patients with nephropathy is much lower than in diabetic patients without nephropathy. In diabetic nephropathy patients, serum creatinine, urea, HbA1c and TGF-β1 exhibited a highly significant negative correlation with vitamin D status, but eGFR showed a highly significant positive correlation.

Conclusion: Vitamin D status has been found to be poor in all diabetic patients, with a greater drop in diabetic nephropathy patients. In diabetic nephropathy patients, serum creatinine, urea, HbA1c and TGF-β1 exhibited a highly significant negative association with vitamin D status, but eGFR showed a highly significant positive link. Deficiency of vitamin D have role in the development and severity of DN, and showed a highly significant correlation with the regulator of fibrosis, TGF-β1. This finding indicates that vitamin D couldbe an important factor for development and progression of Diabetic nephropathy. So supplementation of vitamin D may slow down progression of DN.